If needed, I could remove the 10 pF and substitute a 5 pF or 15 pF capacitor to fine tune the match. I mounted a 47 pF NP0 ceramic SMT capacitor in the BNC connector itself, followed by a 15 pF and 10 pF parallel NP0 SMT capacitors on the protoboard that the matching network was built on. The mounted BNC showed around 7 pF capacitance, leaving about 71 pF of additional capacitance. I also measured the capacitance of the BNC connector using the nanoVNA and verifying with an autozeroing small capacitance meter. ![]() This made me decide to use a set of parallel capacitors so I could fine tune the value that will provide a close match, this turned out to be a good decision. Large changes in capacitor value will prevent the match to be close to the chart center, no matter the value of the inductor. ![]() Changes in the capacitor value keeps the network from moving along the 50 ohm constant resistance curve to the center. The most sensitive value seemed to be the capacitor. Initially I looked at how the match varies with changes in the component values.
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